This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Diabetic retinopathy (DR) is the leading cause of blindness in the working age population. Unfortunately, there is no cure for this ocular complication. The retinal lesions of DR include microaneurysms, vascular leakage, hemorrhage, macular edema and neovascularization, which ultimately leads to vision impairment or blindness. Histological lesions, such as basement membrane (BM) thickening, pericyte loss and acellular capillaries accompany the clinical lesions that develop, at least in part, due to hyperglycemia. The search for a better understanding of the pathogenesis of DR has relied heavily on animal models of the complications albeit mostly in the rat model. The use of primate models of DR would offer a distinct role in the development and assessment of novel treatments because of its close phylogenetic relationship with the human and similar eye structure and function. The common marmoset (Callithrix jacchus) is a new world monkey that has been used in the search for new treatments for other diseases. These are small primates that weigh less than adult rats yet have eyes that are nearly twice the size of the rat eye. More importantly, our preliminary data indicates that the marmoset retina has a central macula, an important anatomical characteristic present in human retina but absent in the rat retina.